Overview. This figure gives an overview over all currently covered PTMs that can be introduced in PyMOL using PyTMs. Top: A table of the possible modifications in alphabetical order. PTM =?post-translational modification. The columns from left to right contain: name of modification, the PyTMs command that is used to introduce it in the PyMOL API (when not using the GUI menu), a custom property selector name through which the modification can be selected in PyMOL (requires incentive PyMOL version 1.7 or higher), the target amino acid, information on whether N-termini can be modified using the respective function (*=?modifiable, excluding Proline), a summary of charge effects, a group indicator (see below) and lastly selected references. Bottom: A depiction of representative modifications from all classes, grouped by amino acid and modification type. Note that the individual panels A-J correspond to the `group below’ column of the above table. All residues are aligned by the amino acid head, the terminal carboxyl group facing towards the viewer. The base is colored blue and the PTMs in red. Hydrogens are omitted. Groups are labeled as in the table above. For each category the displayed and total number of variants are indicated. The respective defaults for categories are underlined. Configurational diastereomers are indicated with the R or S nomenclature.